| State | Colorado |
|---|---|
| Name | Ash-flow tuff of main volcanic sequence |
| Geologic age | Tertiary |
| Lithologic constituents | Major
Igneous > Volcanic (Pyroclastic-ash flow)ash-flow tuff
|
| References | Tweto, Ogden, 1979, Geologic Map of Colorado: U.S. Geological Survey Special Geologic Map, scale 1:500,000. |
| NGMDB product | |
| Counties | Archuleta - Chaffee - Conejos - Custer - Fremont - Grand - Gunnison - Hinsdale - Jackson - Lake - Larimer - Mineral - Montrose - Ouray - Park - Pitkin - Rio Grande - Saguache - San Juan - San Miguel |